Tendons in box girders of prestressed concrete bridges - Structural considerations and detailing

The design of prestressed concrete structures has significantly advanced in the last years through the use of very large tendons and the application of high strength concrete. Larger spans and slenderness are causing highly utilised cross sections. To avoid failure practical design and careful detailing are essential. When leaving the field of experience special care is required. The task is becoming more difficult as no integrated and comprehensive code of practise is available. In fact general principles of structural mechanics, established engineering design and regulations of standards and technical approvals have to be applied to calculation and structural design. In this article structural considerations and advice for the detailing of prestressed concrete bridges will be given by means of examples. The link between the individual design components will especially be highlighted.